Grate frame construction



Jan. 23, 1934. I R. WATSON 1,944,336

GRATE FRAME CONSTRUCTION Filed March 25, 1930 INVE TOR M W ATTORNEYTPatented Jan. 23, 1934 UNITED STATES GRATE FRAME CONSTRUCTION RobertWatson, Cleveland, Ohio, assignor, by

mesne assignments,

Company, New York,

Maine to Waugh Equipment N. Y.,v a corporation of Application March 25,1930. Serial No. 438,757

3 Claims.

' This invention relates to grates of the type used in locomotives,marine boiler furnaces and for other similar heavy duty purposes. More Yspecifically, the new grate comprises a frame and grate bars supportedtherein, the frame having those parts which constitute fuel-supportingsurface constructed and arranged to supplyair to the fuel so supported,whereby more efficient combustion is obtained and practically the enlotire bottom of the fire box is-made effective.

The co-pending application of Thompson, Serial No. 431,282, filedFebruary 25, 1930, contains a discussion of the disadvantages inherentin w grate constructions of the kind now in common use. It is therepointed out that in ordinary grates used in locomotives, for example,the top of the grate frame supports a part of the fuel bed and since thetop of the frame is solid metal, only a small quantity of air reachesthe fuel on the frame, and this fuel burns sluggishly, with incompletecombustion, loss offuel, and formation of clinkers. When the ordinaryframes are used the effective area of the grate is substantially lessthan the total cross-sectional area of the fire box, since in somegrates, the total area of the top of the grate frame may be as much as15 per cent. of the total area of the fire box. As a consequence thepresence of the dead area represented by the top of the frame reducesthe efiiciency of the fire box to a marked degree.

The present invention is directed to the provision of a grate in whichthese disadvantages are overcome and in this grate, the frame itself isso constructed that air is supplied to the fuel supported on the framequite as effectively as to the fuel carried by the grate bars. In thepreferred embodiment of the invention, the frame consists of a webprovided with sockets for the v trunnions of the grate bars and betweenthe 40- trunnion sockets, the web carries a pluraity of spaced lugsextending downwardly from the top thereof and terminating at the top inprojections which serve as fuel-supporting surfaces. The spaced lugsdefine passages for the upward 15 flow of air along the web and channelsbetween the projections connect with these passages so that air issupplied through the passages and channels to the fuel on the smallsupporting surfaces. With this arrangement, the top of the frame iseffective grate surface and the fuel throughout the entire fuel bedburns with approximately equal combustion efficiency.

For a better understanding of the invention, reference may be had to theaccompanying 55 drawing, in which Fig. 1 is a view of a'frame member ofthe new grate in side elevation;

Fig. 2 is a plan view of a portion of the new grate;

Fig. 3 is a fragmentary View in side elevation of a center frame memberof the invention on an enlarged scale;

Fig. 4 is a plan view of the construction illustrated in Fig. 3;

Figs. 5 and 6 are sectional views on the lines 5-5 and 6-6 of Fig. 3,respectively;

Fig. '7 is a plan view on an enlarged scale of a side frame member ofthe invention; and

'Figs; 8 and 9 are sectional views on the lines 8-8 and '9-9 of Fig. 7.

Referring now to the drawing, the grate is illustrated as comprising acenter frame member 10 and two side frame members 11, only one of whichis shown, grate bars 12 being mounted between each side frame member andthe center frame member. The center frame member 10 comprises a websection 13 with a bottom strengthening flange 14 and at its top has aplurality of spaced trunnion sockets 15 defined by ribs 16. Thesetrunnion sockets lie at the top edge of the web and the web isstrengthened by ribs 17 extending downwardly from the bottom of each rib16 of a socket. Between the sockets, the frame may have openings 18 forlightness, these openings being defined by strengthening ribs 19. Alongthe upper edge of the web. are spaced lugs 20, these lugs having adecreasing width in a direction downward from the top of the frame todefine air passages 21 between them which gradually decrease in sizetoward the top of the frame. At the top of each lug there is anupstanding projection 22, the top of which provides fuel-supportingsurface. These projections taper in size in an upward direction so thattheir tops are of substantially less area than their bases. The top ofthe web member of the frame, as indicated in Fig. 6, is formed withsloping surfaces 23 between adjacent projections, these surfaces beinginclined downwardly away from the center line of the web. The lugs inthe two rows on opposite sides of the web are in registry and betweenthe projections on each pair of registering lugs, there is formed achannel 24 for the flow of air. As indicated in Fig. 3, each channel isformed with surfaces 25, which incline down toward the space betweenadjacent projections.

The center frame member is provided with supporting lugs 26 at its endsand it is preferably made with its greatest width at its mid-point, asillustrated in Fig. 1, the width of the frame defob creasing from themid-point toward the ends. The top of the center frame member issufficiently wide so that the trunnion sockets are long enough toreceive the trunnions 2'7 of a pair of grate bars which lie in alignmentat opposite sides of the frame member.

Along each side of the fire box is mounted a side frame member 11comprising a web 28 which is provided along its inner face near its topwith lugs 29 spaced apart to define air passages. 30 between them. Eachlug has a projection at its top similar to the projections 22 at thetops of the lugs on the center frame member and the face of the web iscut away at 31 between adjacent lugs to form downwardly sloping surfacesleading to the passages 30. The top of the frame member is provided withtrunnion sockets 32 at suitably spaced points.

In installing the new grate, the side and center frame members aremounted in position in the usual way and thereafter the grate bars areplaced in the frame with their trunnions supported in aligned sockets inthe center frame member and one side frame member. These grate bars maybe of any suitable or convenient construction, although I prefer to,employ that disclosed in the Buckley application, Serial No. 338,352,filed February 8, 1929.

It will be observed that the top of the grate frame is no longer solidbut fuel is supported thereon on a multiplicity of relatively smallsurfaces which form the tops of the projections 22.

The fuel on the frame is, therefore, in contact with dead surface ofonly relatively small area and air may flow to the fuel on all foursides of each projection. Air flows .up through the passages 21 and 30to the fuel and also flows over the top of the web of the center framemember and laterally through the channels 24. The distribution of airobtained in this manner insures that the fuel supported on the framewill be burned with substantially the same degree of efficiency obtainedin those parts of the fire bed which are supported on the grate bars.Therefore, the top of the grate frame instead of representing dead areathroughout the grate which reduces the total efficiency of the grate nowserves as active combustion surface. In addition, the provision of meansfor supplying air to the fuel on the grate frame prevents the frame fromburning out and the life of the equipment is thus substantiallylengthened. The lugs and projections which are formed at the tops of theframe members may be readily formed during the casting of the membersand thus do not add substantially to the cost of the complete grate.

What I claim:

1. In a grate, a frame member comprising a web having spaced trunnionsockets in its upper edge in part defined by outwardly projecting ribs,rows of spaced lugs on opposite faces of said web near the top thereof,the lugs on opposite faces of the web being in registry and adjacentlugs in a row defining vertical passages for the flow of air betweenthem, a projection extending upwardly from the top of each lug toprovide a fuel support, and a plurality of approximately horizontal airchannels across the top of said web between adjacent projections andalso between registering projections, said channels communicating withsaid air passages.

2. In a grate, a frame member comprising a web having trunnion socketsformed in its upper edge, and rows of spaced lugs on opposite faces ofsaid web andintegral therewith, said lugs extending vertically andterminating adjacent the top of the web, the lugs on opposite faces ofthe web being in registry, fuel-supporting projections, each extendingupwardly from the top of a lug,

each'projection having a top surface of less size than the top of thelug, air passages between adjacent lugs for leading airto the fuelsupported on said projections, and air channels between adjacentprojections and also between registering projections on opposite sidesof said web, the bottoms of said channels leading downwardly from themid-points thereof to form surfaces along which ash may slide.

3. In a grate, a frame member comprising a web having a portion at itsupper edge of gradually increasing thickness in an upward direction,open top trunnion sockets spaced at intervals along the top of saidmember, each socket having one end closed by a portion of said framemember and at least part of each socket lying within said portion ofincreasing thickness, and a plurality of spaced vertical lugs projectingoutward from said portion of the web, said lugs providing vertical airpassages between them, and the top of the member between adjacent lugsbeing cut away to form approximately horizontal air channels for flow ofair from said passages over the top of said member.

ROBERT WATSON.

